body #sky{
  background: #eef;
  height: 100vh;
  overflow: hidden;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
      -ms-flex-pack: center;
          justify-content: center;
  -webkit-box-align: center;
      -ms-flex-align: center;
          align-items: center;
}

#sky {
  margin-top: -60px;
  -webkit-perspective: 400px;
          perspective: 400px;
  -webkit-filter: drop-shadow(0px 150px 10px rgba(0, 0, 0, 0.2));
          filter: drop-shadow(0px 150px 10px rgba(0, 0, 0, 0.2));
  -webkit-transform-style: preserve-3d;
          transform-style: preserve-3d;
}
#sky div {
  -webkit-transform-style: preserve-3d;
          transform-style: preserve-3d;
}
#sky .bird {
  -webkit-animation: fly 10000ms linear infinite;
          animation: fly 10000ms linear infinite;
}
#sky .bird .wind {
  position: absolute;
  left: 50%;
  width: 4px;
  height: 200px;
  margin-left: -2px;
  border-radius: 999px;
  overflow: hidden;
}
#sky .bird .wind:nth-child(1) {
  -webkit-transform: translate3d(-122px, -30px, -86px) rotateY(90deg);
          transform: translate3d(-122px, -30px, -86px) rotateY(90deg);
}
#sky .bird .wind:nth-child(1)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 126, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 1236ms 2599ms linear infinite;
          animation: wind 1236ms 2599ms linear infinite;
}
#sky .bird .wind:nth-child(2) {
  -webkit-transform: translate3d(32px, -121px, -34px) rotateY(90deg);
          transform: translate3d(32px, -121px, -34px) rotateY(90deg);
}
#sky .bird .wind:nth-child(2)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 70, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 2177ms 1587ms linear infinite;
          animation: wind 2177ms 1587ms linear infinite;
}
#sky .bird .wind:nth-child(3) {
  -webkit-transform: translate3d(138px, -74px, -87px) rotateY(90deg);
          transform: translate3d(138px, -74px, -87px) rotateY(90deg);
}
#sky .bird .wind:nth-child(3)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 39, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 1678ms 4564ms linear infinite;
          animation: wind 1678ms 4564ms linear infinite;
}
#sky .bird .wind:nth-child(4) {
  -webkit-transform: translate3d(85px, 120px, -30px) rotateY(90deg);
          transform: translate3d(85px, 120px, -30px) rotateY(90deg);
}
#sky .bird .wind:nth-child(4)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 175, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 2543ms 2190ms linear infinite;
          animation: wind 2543ms 2190ms linear infinite;
}
#sky .bird .wind:nth-child(5) {
  -webkit-transform: translate3d(-164px, 50px, 80px) rotateY(90deg);
          transform: translate3d(-164px, 50px, 80px) rotateY(90deg);
}
#sky .bird .wind:nth-child(5)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 135, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 2320ms 1941ms linear infinite;
          animation: wind 2320ms 1941ms linear infinite;
}
#sky .bird .wind:nth-child(6) {
  -webkit-transform: translate3d(-128px, -33px, -46px) rotateY(90deg);
          transform: translate3d(-128px, -33px, -46px) rotateY(90deg);
}
#sky .bird .wind:nth-child(6)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 136, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 2906ms 2276ms linear infinite;
          animation: wind 2906ms 2276ms linear infinite;
}
#sky .bird .wind:nth-child(7) {
  -webkit-transform: translate3d(188px, -79px, -86px) rotateY(90deg);
          transform: translate3d(188px, -79px, -86px) rotateY(90deg);
}
#sky .bird .wind:nth-child(7)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 24, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 1960ms 1181ms linear infinite;
          animation: wind 1960ms 1181ms linear infinite;
}
#sky .bird .wind:nth-child(8) {
  -webkit-transform: translate3d(7px, -72px, -3px) rotateY(90deg);
          transform: translate3d(7px, -72px, -3px) rotateY(90deg);
}
#sky .bird .wind:nth-child(8)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 165, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 1514ms 2132ms linear infinite;
          animation: wind 1514ms 2132ms linear infinite;
}
#sky .bird .wind:nth-child(9) {
  -webkit-transform: translate3d(48px, 29px, -22px) rotateY(90deg);
          transform: translate3d(48px, 29px, -22px) rotateY(90deg);
}
#sky .bird .wind:nth-child(9)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 102, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 2159ms 4594ms linear infinite;
          animation: wind 2159ms 4594ms linear infinite;
}
#sky .bird .wind:nth-child(10) {
  -webkit-transform: translate3d(67px, 98px, -65px) rotateY(90deg);
          transform: translate3d(67px, 98px, -65px) rotateY(90deg);
}
#sky .bird .wind:nth-child(10)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 177, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 1345ms 3194ms linear infinite;
          animation: wind 1345ms 3194ms linear infinite;
}
#sky .bird .wind:nth-child(11) {
  -webkit-transform: translate3d(158px, 133px, 6px) rotateY(90deg);
          transform: translate3d(158px, 133px, 6px) rotateY(90deg);
}
#sky .bird .wind:nth-child(11)::before {
  content: '';
  position: absolute;
  width: 4px;
  height: 300px;
  background: rgba(100, 200, 181, 0.3);
  border-radius: 999px;
  -webkit-transform: translateY(-300px);
          transform: translateY(-300px);
  -webkit-animation: wind 1130ms 2202ms linear infinite;
          animation: wind 1130ms 2202ms linear infinite;
}
#sky .bird_body {
  position: relative;
  width: 30px;
  height: 40px;
  background: #bbafe6;
}
#sky .bird_head {
  position: absolute;
  top: -30px;
  border-right: 15px solid transparent;
  border-bottom: 30px solid #c4a4e5;
  border-left: 15px solid transparent;
  -webkit-transform-origin: 50% 100%;
          transform-origin: 50% 100%;
  -webkit-transform: rotateX(-20deg);
          transform: rotateX(-20deg);
}
#sky .bird_wing_left {
  position: absolute;
  left: -30px;
  height: 30px;
  border-right: 30px solid #8997f5;
  border-bottom: 10px solid transparent;
  -webkit-transform-origin: 100% 0;
          transform-origin: 100% 0;
  -webkit-animation: wingLeft 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
          animation: wingLeft 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
}
#sky .bird_wing_left_top {
  position: absolute;
  left: -30px;
  border-right: 30px solid #b670ec;
  border-bottom: 30px solid transparent;
  -webkit-transform-origin: 100% 0;
          transform-origin: 100% 0;
  -webkit-animation: wingLeft 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
          animation: wingLeft 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
}
#sky .bird_wing_right {
  position: absolute;
  left: 30px;
  height: 30px;
  border-left: 30px solid #b8a0f4;
  border-bottom: 10px solid transparent;
  -webkit-transform-origin: 0 0;
          transform-origin: 0 0;
  -webkit-animation: wingRight 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
          animation: wingRight 1000ms cubic-bezier(0.36, 0.1, 0.16, 1) infinite alternate;
}
#sky .bird_wing_right_top {
  position: absolute;
  border-left: 30px solid #ac96f1;
  border-bottom: 30px solid transparent;
  -webkit-transform-origin: 0 0;
          transform-origin: 0 0;
  -webkit-animation: wingRight 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
          animation: wingRight 1000ms cubic-bezier(0.545, 0.08, 0.52, 0.975) infinite alternate;
}
#sky .bird_tail_left {
  position: absolute;
  top: 40px;
  border-right: 30px solid transparent;
  border-top: 40px solid #7471cf;
  -webkit-transform-origin: 50% 0;
          transform-origin: 50% 0;
  -webkit-transform: rotateX(-20deg);
          transform: rotateX(-20deg);
}
#sky .bird_tail_right {
  position: absolute;
  top: 40px;
  border-left: 30px solid transparent;
  border-top: 40px solid #6cbed9;
  -webkit-transform-origin: 50% 0;
          transform-origin: 50% 0;
  -webkit-transform: rotateX(-20deg);
          transform: rotateX(-20deg);
}

@-webkit-keyframes fly {
  0% {
    -webkit-transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
            transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
  }
  100% {
    -webkit-transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
            transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
  }
}

@keyframes fly {
  0% {
    -webkit-transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
            transform: rotateX(-120deg) rotateZ(0deg) rotateX(10deg);
  }
  100% {
    -webkit-transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
            transform: rotateX(-120deg) rotateZ(360deg) rotateX(10deg);
  }
}
@-webkit-keyframes wingLeft {
  0% {
    -webkit-transform: rotateY(-40deg);
            transform: rotateY(-40deg);
  }
  100% {
    -webkit-transform: rotateY(40deg);
            transform: rotateY(40deg);
  }
}
@keyframes wingLeft {
  0% {
    -webkit-transform: rotateY(-40deg);
            transform: rotateY(-40deg);
  }
  100% {
    -webkit-transform: rotateY(40deg);
            transform: rotateY(40deg);
  }
}
@-webkit-keyframes wingRight {
  0% {
    -webkit-transform: rotateY(40deg);
            transform: rotateY(40deg);
  }
  100% {
    -webkit-transform: rotateY(-40deg);
            transform: rotateY(-40deg);
  }
}
@keyframes wingRight {
  0% {
    -webkit-transform: rotateY(40deg);
            transform: rotateY(40deg);
  }
  100% {
    -webkit-transform: rotateY(-40deg);
            transform: rotateY(-40deg);
  }
}
@-webkit-keyframes wind {
  0% {
    -webkit-transform: translateY(-300px);
            transform: translateY(-300px);
  }
  100% {
    -webkit-transform: translateY(200px);
            transform: translateY(200px);
  }
}
@keyframes wind {
  0% {
    -webkit-transform: translateY(-300px);
            transform: translateY(-300px);
  }
  100% {
    -webkit-transform: translateY(200px);
            transform: translateY(200px);
  }
}
